msh_exec.cpp File Reference

Execution related utilities. More...

Functions
int	msh_exec_script (const char *path)
	Executes a script line by line.
int	msh_execve (char **argv)
	Executes a command.
int	msh_exec_simple (simple_command &cmd, int pipe_in=STDIN_FILENO, int pipe_out=STDOUT_FILENO, int flags=0)
	Executes a simple command.
int	msh_exec_internal (command &cmd, int in, int out, int flags)
	Internal command execution function.

Variables
int	exec_line_no = 0
	The current line number of the script being executed.
std::string	exec_path
	The path to the script being executed.

Detailed Description

Execution related utilities.

Function Documentation

msh_exec_internal()

int msh_exec_internal	(	command &	cmd,
		int	in,
		int	out,
		int	flags )

Internal command execution function.

Delegates the execution to the appropriate function based on the command type holded by the cmd.cmd variant object.

Parameters

cmd	The command to execute.
in	File descriptor to use as stdin.
out	File descriptor to use as stdout.
flags	Flags to pass to the command.

Returns

Exit status of the command or the error code if any.

msh_exec_script()

int msh_exec_script

(

const char *

path

)

Executes a script line by line.

Warning

Caller must ensure that the file exists and is readable.

exec_path and exec_line_no are set for error_log().

See also

error_log()

Parameters

path	Path to the script.

Returns

Exit status of the script.

See also

msh_execve

msh_exec_simple()

int msh_exec_simple	(	simple_command &	cmd,
		int	pipe_in = STDIN_FILENO,
		int	pipe_out = STDOUT_FILENO,
		int	flags = 0 )

Executes a simple command.

Parameters

cmd	The command to execute.
pipe_in	File descriptor to use as stdin.
pipe_out	File descriptor to use as stdout.
flags	Flags to pass to the command.

Returns

Exit status of the command or the error code if any.

If the command is a builtin, it is executed directly. Otherwise, it is executed using msh_execve().

If either pipe_in or pipe_out is not STDIN_FILENO or STDOUT_FILENO respectively, the command is not a builtin, or the command is executed asynchronously, the command will be executed in a forked process.

If either ASYNC or FORK_NO_WAIT is set in flags, the parent process returns immediately. One should take care of the child process by calling wait_for_process() or reap_children() explicitly if needed.

See also

msh_execve

msh_execve()

int msh_execve

(

char **

argv

)

Executes a command.

Parameters

argv	Array of arguments.

Returns

Exit status of the command.

If command contains a slash, it is executed directly, supposing it is a full path to the executable. Otherwise, the command is searched in the PATH environment variable using execvpe(). If execve() fails and errno is ENOEXEC, the command is treated as a script and executed using msh_exec_script().

See also

execve

execvpe

msh_exec_script

Variable Documentation

exec_line_no

int exec_line_no = 0

The current line number of the script being executed.

Undefined if no script is being executed.

See also

msh_exec_script

exec_path

std::string exec_path

The path to the script being executed.

Undefined if no script is being executed.

See also

msh_exec_script